There is heightened awareness of fire prevention in homes and businesses in the United States. This awareness has led to the development of standards and legislation directed to reducing the risk of fires, particularly with respect to bedding and upholstered furniture. Conventional fire prevention techniques for bedding and upholstered furniture involve the topical application of flame retardant chemicals directly to an outer decorative layer of upholstery material.
However, recently passed legislation may render conventional fire protection techniques for bedding (particularly mattresses) inadequate. For example, the cigarette burn test for measuring flame resistance (developed by the Upholstered Furniture Action Council) has been deemed inadequate by the state of California and by the U.S. Consumer Product Safety Commission. For example, in January, 2005, California implemented regulatory legislation requiring mattresses to be flame resistant (California Technical Bulletin 603 of the State of California Department of Consumer Affairs, referred to as “TB-603”). Aggressive federal standards for flammability of mattresses set forth by the U.S. Consumer Product Safety Commission require flame resistant construction for all mattresses sold in the United States and are described in the Federal Register at 16 CFR 1633 (hereinafter “16 CFR 1633”), which is incorporated herein by reference in its entirety. The testing specified by 16 CFR 1633 exposes a mattress side and top and a side of a foundation to a gas burner flame. Following the exposure, the mattress and foundation are monitored for thirty minutes to measure heat generation rate and total heat generation.
The top and side panels of a mattress are typically composed of layers of material. For example, the outer layer may be a decorative fabric referred to as ticking or a ticking layer, and which may be a high quality knit or woven textile. Mattress ticking fabrics are generally of loose construction and have a soft, extensible handle. A coating on the back or a laminated fabric on the back may be necessary to provide dimensional stability and wear resistance.
The next layer is typically a cushioning layer (or layers), such as foam, batting, or other lofty, soft material (or combinations of various soft materials). The cushioning layer provides a plump, soft, feel and texture to the panel. The next layer is typically a backing fabric that supports the cushioning material and provides strength and dimensional stability to the panel. The backing layer may be optional if the second layer is strong enough and stable enough to support the structure. Additionally, some mattress or upholstery panels are flat and do not have significant ‘plumping’ or cushioning, but must still provide the insulation and flame resistance required by the new standards. The backing layer is conventionally a polyester or polypropylene nonwoven fabric, a knit, or a woven fabric. The layers of a mattress panel are typically assembled via stitch quilting. Conventionally, a flame and heat blocking component is added to the panel when the panel is designed to resist heat, fire, or ignition.
When mattresses and other upholstered articles having a ticking layer are exposed to fire, or to a test flame challenge, the first material to be exposed is the ticking layer. Ticking fabrics can be made to be flame resistant by finishing the ticking fabric with flame retardant chemicals, or by back-coating the ticking fabric with flame retardant chemicals. Unfortunately, conventional finishing and back coating techniques may cause unacceptable changes to the ticking fabric, such as stiffening, discoloration, fiber blend limitations, and may cause exposure of individuals to chemicals on the sleep surface. Moreover, these conventional finishing and back-coating techniques may have a high degree of variability, may give unreliable performance, and may increase manufacturing costs.
To prevent the ignition of the core of a mattress, the core of an article of upholstered furniture, or other upholstered article, a variety of flame resistant materials have been utilized. For example, fabrics made from graphite, carbon, para-aramid, or other flame and heat resistant fibers have been used. Batting composed of flame resistant fibers or fibers that char, such as silica modified rayon (or Visil), modacrylic, FR rayon, FR polyester, melamine, or other suitable fibers, may be produced such that high basis weights can provide flame resistance and insulation. Foams may be chemically treated with flame retardant or impregnated with graphite. Fabrics may also be treated with flame retardant and/or intumescent chemical compositions or impregnated with intumescent chemicals to provide flame blocking and insulative properties.
Conventional ticking burns rapidly and can generate more than 15 MJ of heat in the first 10 minutes when exposed to a flame challenge per 16 CFR 1633 testing. Even though a mattress core is protected with conventional barrier materials, the mattress can fail testing and present significant flammability risk because of the ticking layer, or flaws in the ticking layer. The tendency to propagate flame and spread fire over the ticking surface is detrimental to the performance of upholstery and ticking fabrics used in furniture and mattress construction.